Evidence for an early terrestrial food web: coprolites from the Early Devonian Rhynie chert

2003 ◽  
Vol 94 (4) ◽  
pp. 371-389 ◽  
Author(s):  
Kate S. Habgood ◽  
Hagen Hass ◽  
Hans Kerp

ABSTRACTFossils in the Pragian Rhynie cherts, Aberdeenshire, Scotland, are preserved with exquisite cellular detail, and provide much information on Early Devonian terrestrial and freshwater ecosystems. The fossils include abundant and diverse coprolites which demonstrate the existence of consumers differing in life-habit and diet. The coprolites are small (0.5–3 mm) and diverse in morphology and content, including groups of amorphous coprolites as well as coprolites with identifiable, particulate content. The present authors define three new ichnogenera to accommodate these coprolites: •Lancifaex encompasses elongate coprolites with particulate content, and includes three ichnospecies, distinguished on morphology, L. simplex, L. divisa and L. moniliforma.•Rotundafaex encompasses rotund coprolites with particulate content, and includes a single ichnospecies, R. aggregata.•Bacillafaex encompasses rod-shaped coprolites with amorphous content, and includes two ichnospecies, distinguished on size, B. constipatus and B. mina. Typically, plant spores do not dominate the content of these coprolites, but the population does include some spore-rich coprolites. The presence of spore-rich coprolites in this diverse assemblage adds evidence to the debate on spore-feeding as a nutritional strategy in early terrestrial ecosystems. The authors conclude that the coprolites described here indicate at least four types of consumer including detritivores and herbivores. Spore-rich coprolites might suggest sporivory; however, comparison with the faeces of modern millipedes demonstrates that they might equally well be the product of detritivores. The continuum observed here between spore-rich and spore-poor coprolites implies that, in this assemblage, spore-rich coprolites do not constitute a distinct group. Rather, they are part of a group of elongate, ellipsoidal coprolites with heterogeneous content that includes, at one extreme, coprolites which lack plant spores, and at the other, coprolites which contain abundant plant spores. Most coprolites in this group fall somewhere between the two extr

Zootaxa ◽  
2021 ◽  
Vol 4915 (2) ◽  
pp. 294-298
Author(s):  
ABEL PÉREZ-GONZÁLEZ ◽  
JEFFREY W. SHULTZ

Harvestmen (Arachnida: Opiliones) were among the earliest terrestrial arthropods but their unmineralized exoskeletons are scarce and often fragmentary as fossils (Palencia et al. 2019). Consequently, the discovery and interpretations of fossil harvestmen from the early Palaeozoic can have disproportionate effects on the understanding of evolution in Opiliones. Recently, Devonopilio hutchinsoni Tihelka, Tian & Cai, 2020, was described as a new fossil harvestman from the well-known Rhynie chert deposits of Scotland, an important source of information on freshwater and terrestrial ecosystems of the early Devonian (Tihelka et al. 2020). This species would be one of the earliest records of harvestmen. The description was based on a single slide showing fragments of arthropod cuticle, which Tihelka et al. interpreted as a harvestmen penis and unspecified associated body parts. As specialists on harvestman morphology and systematics, we were intrigued by these conclusions. However, based on the material presented by Tihelka et al. we find no compelling evidence supporting the proposal that the specimen is a harvestman. 


1967 ◽  
Vol 28 ◽  
pp. 177-206
Author(s):  
J. B. Oke ◽  
C. A. Whitney

Pecker:The topic to be considered today is the continuous spectrum of certain stars, whose variability we attribute to a pulsation of some part of their structure. Obviously, this continuous spectrum provides a test of the pulsation theory to the extent that the continuum is completely and accurately observed and that we can analyse it to infer the structure of the star producing it. The continuum is one of the two possible spectral observations; the other is the line spectrum. It is obvious that from studies of the continuum alone, we obtain no direct information on the velocity fields in the star. We obtain information only on the thermodynamic structure of the photospheric layers of these stars–the photospheric layers being defined as those from which the observed continuum directly arises. So the problems arising in a study of the continuum are of two general kinds: completeness of observation, and adequacy of diagnostic interpretation. I will make a few comments on these, then turn the meeting over to Oke and Whitney.


2014 ◽  
Vol 45 (2) ◽  
pp. 167-178 ◽  
Author(s):  
Steven C. Hertler

Abstract The five factor trait of conscientiousnessis a supertrait, denoting on one hand a pattern of excessive labor, rigidity, orderliness and compulsivity,and on the other hand a pattern of strict rectitude, scrupulosity, dutifulness and morality. In both respects the obsessive-compulsive personality is conscientious; indeed, it has been labeled a disorder of extreme conscientiousness (Widiger et al., 2009). Antisocial personality disorder, in the present paper, is described as occupying the opposite end of the conscientiousness continuum. The antisocial is impulsive rather than compulsive, illicit rather than licit, and furtive rather than forthright.After clinically comparing the obsessive and antisocial personalities, the present paper invokes evolutionary theory to explain their resultant behavioral, ideological, political and demographic differences.


2014 ◽  
Vol 58 (1) ◽  
pp. 13-22
Author(s):  
Roman Wituła ◽  
Edyta Hetmaniok ◽  
Damian Słota

Abstract In the paper we present the selected properties of composition relation of the convergent and divergent permutations connected with commutation. We note that a permutation on ℕ is called the convergent permutation if for each convergent series ∑an of real terms, the p-rearranged series ∑ap(n) is also convergent. All the other permutations on ℕ are called the divergent permutations. We have proven, among others, that, for many permutations p on ℕ, the family of divergent permutations q on ℕ commuting with p possesses cardinality of the continuum. For example, the permutations p on ℕ having finite order possess this property. On the other hand, an example of a convergent permutation which commutes only with some convergent permutations is also presented.


1969 ◽  
Vol 73 (700) ◽  
pp. 255-270
Author(s):  
H. Caplan

The purpose of this prologue is to outline how I have approached the arrogant and impossible task of surveying an unborn century of law. I may also be able to illustrate that the nature and quality of the task is completely different from that attempted in the preceding papers. In the whole paper I have done little more than infer repeatedly, in different ways (a) that the shape of the future so far as law is concerned will be determined by the methods of communication adopted between sectors of the aerospace community and between the aerospace community and society at large, and (b) that the search for effective methods of communication is urgent. But my target is not the lawyers of our community—who I am not qualified to advise. I write for the other members of the Royal Aeronautical Society and I return to the task of persuading them that they have a role to play in evolving future laws for aerospace activities.


1983 ◽  
Vol 25 (4) ◽  
pp. 593-616 ◽  
Author(s):  
Michael H. Fisher

A marriage expresses a mutual recognition of some degree of shared identity. The wedding ceremony confirms these links and creates new ones, although to an extent variable with the culture and the specific case. The affinity can be between individuals acting for themselves, for families, or for larger social or national groups. At one extreme would be the temporary liason, stemming from personal whim or passion, between individuals who share little more than common acceptance of the culture which recognizes the form. A Las Vegas marriage followed by a quickie Mexican divorce, a Hindu Gāndharva marriage consummated without any ceremony, or a Shi'i mut 'ah (marriage of pleasure) of contractually stipulated length might typify this end of the continuum. At the other end would be the purely political marriage that links social groups, parties, or even nations together but which disregards the desires of the principals. Richard II's diplomatic marriage to Eleanor of Aquitaine, a Kulin Brahmin's ritual marriage with dozens of women, or Asaf al-Daula's apparently unconsummated marriage with Shams al-Nisā' Begum (discussed later) exemplifies this extreme. Between lie a diversity of forms within a variety of cultures.


2014 ◽  
Vol 10 (1) ◽  
pp. 81-108 ◽  
Author(s):  
Blake E. Ashforth ◽  
Glen E. Kreiner

The literature on dirty work has focused on what physically (e.g., garbage collectors), socially (e.g., addiction counsellors), and morally (e.g., exotic dancers) stigmatized occupations have in common, implying that dirty work is a relatively monolithic construct. In this article, we focus on thedifferencesbetween these three forms of dirty work and how occupational members collectively attempt to counter the particular stigma associated with each. We argue that the largest differences are between moral dirty work and the other two forms; if physical and social dirty work tend to be seen as more necessary than evil, then moral dirty work tends to be seen as more evil than necessary. Moral dirty work typically constitutes a graver identity threat to occupational members, fostering greater entitativity (a sense of being a distinct group), a greater reliance on members as social buffers, and a greater use of condemning condemners and organization-level defensive tactics. We develop a series of propositions to formalize our arguments and suggest how this more nuanced approach to studying dirty work can stimulate and inform future research.


2007 ◽  
Vol 3 (S242) ◽  
pp. 180-181
Author(s):  
M. A. Trinidad ◽  
S. Curiel ◽  
J. M. Torrelles ◽  
L. F. Rodríguez ◽  
V. Migenes ◽  
...  

AbstractWe present simultaneous observations of continuum (3.5 and 1.3cm) and water maser line emission (1.3cm) carried out with the VLA-A toward the high-mass object IRAS 23139+5939. We detected two radio continuum sources at 3.5cm separated by 0”5 (~2400 AU), I23139 and I23139S. Based on the observed continuum flux density and the spectral index, we suggest that I23139 is a thermal radio jet associated with a high-mass YSO. On the other hand, based on the spatio-kinematical distribution of the water masers, together with the continuum emission information, we speculate that I23139S is also a jet source powering some of the masers detected in the region.


2021 ◽  
Vol 64 (5) ◽  
pp. 1569-1579
Author(s):  
Fei Hu ◽  
Bin Cheng ◽  
Lingjuan Wang-Li

HighlightsParticulate matter (PM) data were analyzed to identify PM emission characteristics among different animal types.The PM concentrations were higher in broiler chicken and swine farrowing houses and were higher in winter.The PM emissions were also higher in broiler chicken houses and swine farrowing rooms.The PM in the layer chicken house in Indiana had narrower distributions with a greater percentage of smaller particles.Abstract. Understanding the characteristics of particulate matter (PM) emissions from animal feeding operations (AFOs) is essential to address the associated health and environmental impacts and to develop control strategies to mitigate such impacts. This article reports a study of PM concentrations and emission characteristics from 26 poultry and swine production houses to investigate the similarities and differences in PM emission characteristics, e.g., concentrations, emission rates, and particle size distribution (PSD), among different animal and housing types. Concentration and emission data for PM2.5, PM10, and total suspended particulates (TSP) collected by the National Air Emission Monitoring Study (NAEMS) were used to compare the differences among different production practices and animal types. The PSDs of the PM were examined based on the PM2.5/PM10 and PM10/TSP emission rate ratios. It was discovered that the concentrations of PM varied among animal types. For poultry, the concentrations of PM were higher in broiler houses than in other poultry houses. For swine, the average concentrations of PM were higher in farrowing rooms than in swine barns. Moreover, the PM concentrations in poultry and swine houses exhibited significant seasonal trends, with higher concentrations in winter and lower concentrations in summer, which were in a reverse relationship with ventilation rates. The PM emissions also varied among animal types. For poultry, the PM emissions were significantly higher for poultry production houses in California. For swine, the PM emissions were significantly higher for farrowing rooms than other swine houses. The PSD of PM varied among animal types, with mass median diameters (MMD) in the ranges of 6.51 to 13.62 µm for poultry houses and 7.94 to 17.19 µm for swine houses. The geometric standard deviations (GSD) were in the ranges of 1.66 to 2.71 and 1.65 to 2.9 for poultry and swine PM, respectively. The PM in the layer house in Indiana had a narrower distribution (smaller GSD) with a greater percentage of smaller particles than the other poultry houses, while the PM in the broiler house in California had a broader distribution (larger GSD) than the other poultry houses. For swine, the PM in the sow barn in North Carolina had a narrower distribution (smaller GSD) than the other swine houses, while the PM in the farrowing houses in Oklahoma had a broader distribution (larger GSD) than the other swine houses. The knowledge gained from this research may provide insights for addressing the PM emissions from various animal production systems. Keywords: Concentration and emission, Particulate matter, PM2.5, PM10, Poultry, swine, PSD, TSP.


2020 ◽  
Author(s):  
Anik Banik ◽  
Md. Fuad Mondal ◽  
Md. Mostafigur Rahman Khan ◽  
Sheikh Rashel Ahmed ◽  
Md. Mehedi Hasan

AbstractThe locust problem is a global threat for food security. Locusts can fly and migrate overseas within a zip and creating a large-scale devastation to the diversified agro-ecosystem. GIS based analysis showed the recent movement of locusts, among them Schistocerca gregaria and Locusta migratoria are predominant in Indian subcontinent and are found more notorious and devastating one. This devastation needs to be stopped to save human race from food deprivation. In our study, we screened some commonly used agricultural pesticides and strongly recommended three of them viz. biphenthrin, diafenthiuron and silafluofen which might be potential to control the desert locusts based on their binding affinity towards the locust’s survival proteins. Our phylogenetic analysis reveals that these three recommended pesticides might also show potency to the other locust species as well as they are also way safer than the other commercially available pesticides. These proposed pesticide’s bioactive analogs from fungus and bacteria may also show efficacy as next generation controlling measures of locust as well as different kind of pests. These recommended pesticides are expected to be highly effective against locusts and needs to bring forward by the entomologists’ by performing experimental field trials.HighlightsGIS map unmasked the 2020 migratory pattern of locusts which now predominant towards Indian subcontinent.Biphenthrin, diafenthiuron and silafluofen showed maximum binding affinity.Biphenthrin and diafenthiuron were relatively safer than silafluofen.Bioactive analogs from fungus and bacteria could be an alternative to control locusts.Pesticides inhibition hotspots for desert locusts were unrevealed.


Sign in / Sign up

Export Citation Format

Share Document